The subject invention relates to an improved bearing structure for radiating fans, and in particularly to one with a ring shaped groove along the radius on the inside of the bearing and a shaft rod mounted in the bearing so that when the shaft rod rotates continuously with the fan blades, the groove will enable the bearing to have an increased oil containing area, to minimize friction between the shaft rod and the bearing, and to extend its service life.
Conventionally, a regular electric fan is installed within the framework of a frame unit. At the center of the frame unit is a bearing carrier and at the center of the bearing carrier is a protruding hollow post. In the hollow post is an oil containing bearing, and surrounding the hollow post is mounted a stator. On the stator is mounted a fan unit, and surrounding the fan unit are several spiral shaped fan blades, the fan unit including a groove that accommodates the bearing carrier. In the groove is fixed an upright shaft rod that is made of stainless steel. The other end of the shaft rod is inserted into the bearing in the hollow post, and on the other end of the bearing carrier opposite to the hollow post is a vent that communicates with the hollow post. The vent is covered tightly by an oil cap when the device is in use. Since the bearing is a hollow sleeve with a smooth inside wall and open ends, lubricating oil often will seep out between the bearing and the shaft rod along the smooth inside wall in the bearing, and hence the lubricating oil is used up very soon. The result is friction between the shaft and the bearing and subsequent noise, shortening of the service life of the bearing, and increased manufacturers' costs in procurement and replacement. In order to eliminate the above weakness in the oil containing capacity of the bearing, some would replace it with a roller bearing that requires frequent refilling of lubricating oil. Although this will avoid such weaknesses as loss of lubricating oil and deterioration of the oil after a period of heated operation, the production of such roller bearings requires quite sophisticated and precise manufacturing processing, to produce a ball bearing with a diameter of 0.15 mm-0.20 mm, which costs too much time and labor, and as a result the production costs will be several times higher than the costs for producing oil containing bearings.
To eliminate the weaknesses of the above conventional devices and structures, the subject inventor has devoted extended efforts in intensive research and experiments, and has finally developed and designed the improved bearing structure for radiating fans of the invention.